top of page

Die Casting

Valmark products.png

What is Die Casting?

Die casting is a metalworking process in which molten metal is forced into a mold cavity under high pressure. Die casting is an efficient, economical way to manufacture complex metal parts at scale. The most common metals used in die casting are non-ferrous alloys like Aluminum, Zinc, and Magnesium.

Nearly 200 years old, die casting is a proven process that produces more castings than any other casting method. A Steel mold or “die” is used to achieve as many design features as possible during casting. Parts can be machined after casting for tight-tolerance dimensions and finished with a variety of coating options. By casting standards, die casting offers very good surface finish and dimensional consistency.

How Does Die Casting Work?

Traditional die casting occurs in four steps:

1. Die Preparation

The die is prepared by spraying the mold cavity with lubricant. The lubricant helps control die temperature and assists in the removal of the casting.

2. Filling

The die is held closed while molten metal is injected into the cavity under high pressure — between 1,500 and 25,000 psi. Once the die cavity is filled, the pressure is maintained until the casting solidifies.

3. Ejection

The die is opened and the “shot” is ejected by ejector pins. A shot can contain one or multiple castings, depending on how many cavities are in the die.

4. Shakeout

Finally, the shakeout involves separating the scrap from the shot — including the gate, runners, sprues and flash. The scrap metal is remelted and recycled.

The high-pressure injection fills the die quickly to ensure that the entire cavity fills before any part of the casting solidifies. In this way, continuity is achieved throughout the shot, even if a shape has thin sections that are difficult to fill.

The result is accurate metal parts with more intricate designs than those created by other casting processes. To produce non-castable features, die casters perform secondary operations such as tapping holes, polishing, plating, buffing, and painting.

Natural Cosmetics Oil

Advantages of Die Casting

Die casting offers many advantages, some of which include:

  • Excellent dimensional accuracy

  • Smooth cast surfaces

  • Thinner walls than other casting processes

  • Cast-in inserts — e.g. threaded inserts, heating elements, and high strength bearing surfaces

  • Reduces or eliminates secondary machining operations

  • Rapid production rates

  • High casting tensile strength

  • Slower corrosion rates than other types of castings due to smoother surface finish

Die Casting Materials

Below is a list of the main die casting alloys and their advantages:

  • Aluminum: Lightweight; high dimensional stability for very complex shapes and thin walls; good corrosion resistance; good mechanical properties; high thermal and electrical conductivity; retains strength at high temperatures

  • Zinc: The easiest metal to cast; high ductility; high impact strength; easily plated; economical for small parts; promotes long die life

  • Magnesium: The easiest metal to machine; excellent strength-to-weight ratio; lightest alloy commonly die cast

  • Copper: High hardness; high corrosion resistance; highest mechanical properties of die cast alloys; excellent wear resistance; excellent dimensional stability; strength approaching that of Steel parts

  • Lead and Tin: High density; extremely close dimensional accuracy; used for special forms of corrosion resistance

  • Silicon Tombac: High-strength alloy made of Copper, Zinc and Silicon. Often used as an alternative for investment cast Steel parts

Die Casting Applications

Die casting is used in a wide range of industries and products. Some examples include:

  • Defense: firearms, communications equipment, vehicles, mobility systems, avionics

  • Industrial: bearing housings, compressors, pumps, heatsinks, handheld enclosures

  • Medical: pumps, centrifuges, surgical robots, monitors, operating instruments, hospital beds

  • Technology: RF filters, antenna mounts, front face plates, rugged housings, light fixtures, end caps, heatsinks

  • Transportation: cylinders, chassis, decorative parts, EV battery housings

Die Casting Manufacturers

A&B Die Casting

Industry Association

Die Casting Resources

bottom of page